Satyanto Krido Saptomo

Climate change effects on paddy field thermal environment and evapotranspiration

The effect of air temperature increase from meteorological data on thermal microenvironment of irrigated paddy field is simulated using energy balance model. Statistical test was used to determine the existence of the trend in temperature change of data from meteorological stations in Indonesia. The temperature was tested to have positive trend, and it was used to generate future and past increase of temperature for the simulation. According to the simulation, the change in energy balance occurs following additional heat contributed by the increase of air temperature. The results show that irrigated paddy field seems to have function of decreasing effect of temperature increase whereas, evapotranspiration increases. However, increasing air temperature also increases temperature in paddy system, but seems to be more moderate than in nonpaddy field.

Reliable data delivery mechanism on irrigation monitoring system

Monitoring activity is one of implementation of automatically irrigation system. This activity is closely related to data transmission. Wireless communication channels are not free of noise interferences. This paper proposes the development of monitoring irrigation system with a reliable data delivery mechanisms in which TCP protocol handles senders sending their data to a receiver. The research designs an irrigation system architecture consisting of main and field controllers. The main controller is a receiver as a server that designs with concurrent and connection-oriented mode. The field controller consist of gateway (Raspberry Pi) as a sender, sensor node (Arduino Leonardo), sensor and actuator. In order to ensure the design of the data delivery architecture is well defined, analysis is carried out to calculate throughput, packet loss ratio, and packet delay to verify the design. In addition, the error control features will be added to complement these mechanisms in further research.

Performance of Quasi Real-Time Paddy Field Monitoring Systems in Indonesia

Since 2010 paddy field monitoring systems have been installed in ten locations in Indonesia. Each system performs quasi-real-time monitoring using a FieldRouter equipped with an in situ camera and connected to meteorological and soil data loggers. All parameters are measured and monitored at 30-min intervals. Data and field images are daily transmitted to a remote server through Internet connection. During experiments, field monitoring systems showed good performance in monitoring and transmitting field data. Quasi-real-time monitoring is more power-saving and Internet-cost-effective than real-time monitoring. However, its stability depends on the field solar power supply and Internet connection. If there are any problems with the Internet connection, power supply, or sensors, the field image and the data are lost. For minimizing problems in fields, it is best to involve local residents in maintaining the systems. We plan to develop an advanced data management system for analyzing the data with specific purposes bearing on climate change in the future works. Keywords: monitoring system, paddy fields, system of rice intensification, FieldRouter, quasi real-time.

A Field Monitoring Station Network for Supporting the Development of Integrated Water Resources Management

Field monitoring systems were installed in six locations of interest for field weather and environment monitoring in support of the development of an integrated water resources management system in two watersheds, Saba in Bali province and Jeneberang in South Sulawesi province, Indonesia. The stations were situated in lower, middle, and upper sections of the watersheds, with an intention of obtaining information regarding variation in weather and soil that represents variation in the parameters of the respective watersheds. The systems include an automatic weather station, a soil monitoring system, and a Field Router remote monitoring system that delivers data daily via Internet. Data handling procedures were developed to process the data and calculate the water balance of each field. The result yielded a description of the current condition of each field that can serve as a basis for local field water management assessment. This real-time monitoring network can support water management in watersheds that are facing water-related risks resulting from land-use change and climate change. Keywords: water resources, remote monitoring, climate change, agricultural water management.

Penentuan Awal dan Durasi Musim Kemarau Menggunakan Fungsi Polynomial dengan Aplikasi Visual Basic for Applications (VBA)

Forecasting the occurrence of the onset of dry season and its length is important in determining the availability of water for irrigation, domestic and industrial uses. The length of dry season is used for reference in calculating water demand. Prediction of drought can be studied based on the rainfall patterns that have occurred. This is possible because there is a tendency that the rain will repeat a certain pattern at a certain time. The purpose of this study was to predict the onset of dry and rainy seasons as well as their length. Determination of the onset of dry season and its length was conducted using polynomial function of the cumulative amount of rain every single day based on the rain data. The research was conducted using rainfall data from Climate Station III in Serang from 1989 to 2010. The sum of daily rainfall could form a polynomial function. If the magnitude of daily rainfall in a certain period of time is less than the slope of the cumulative annual rainfall, then at that time the dry season is occurred. Determination of the dry season peak can be done by finding the maximum (extreme) point from the polynomial function by getting the second derivative which value is close or equal to zero. In average, the dry season occurred in Serang city started on the 132nd until 300th day. Deviation value for the onset of dry and rainy seasons were 23 and 38 days, respectively, with an average of length of 168 days. The average of R2 value for polynomial function was 0.9937.

Sistem Akuisisi Data Multi Node untuk Irigasi Otomatis Berbasis Wireless Sensor Network

Watering plants is one of farmer’s activities. Most of Indonesian farmers use traditional watering method to water plants. It causes water productivity unmanaged properly and soil moisture level can not be monitored. To resolve these problems, an automatic watering system is developed. This system uses soil moisture sensors which provide real-time data. Data from multiple sensor node will be transmitted through wireless sensor network. LED in actuator node will turn on or off based on lower and upper set point values transmitted from coordinator node. Soil moisture sensors are calibrated using groundwater level to obtain correlation between sensor and groundwater level. Delay, throughput, and packet loss ratio are measured and result 0.2 seconds, 1.6 kbps, and 1.6%, respectively. These values showed that all automatic watering system were well implemented.

Environmental Assessment in Collaboration with Local Residents

Environmental assessment is key in designing a local framework for integrated water resources management dealing with land-use and climate change. We involved local residents in acquiring environmental data to clarify significant land-use and climate changes in watershed and field scales. In the watershed scale, a series of daily climate data was collected from three automatic weather stations, each available in the upstream, midstream, and downstream areas of the Saba Watershed from 2007 to 2014. The annual rainfall pattern changed; it decreased in all the stations after 2010. The annual rainfall downstream was always lower than at the other two stations located at higher elevations. As a consequence, the downstream area had the earliest and the longest dry season compared to the other areas. In the field scale, climate conditions were assessed on the basis of intensive measurements using automatic weather stations and soil sensors in three representative locations. Based on the monitored data in the context of climate change, the optimal planting date during a year was October 15 (first season), February 13 (second season), and June 12 (third season). We estimated that the irrigation water requirement was 108, 283, and 751 mm, respectively. We recommend constructing a rainwater reservoir to store more irrigation water.

Heat Environment Affected by Different Land Surface Conditions

Study of heat environment and evaporation affected by different surface condition. Observation and simulation of bare, grass and paddy field were performed, which results were compared. The observation was conducted at an experimental farmland. The simulations model used in the study includes numerical model of temperature, wind and humidity distributions in atmospheric boundary layer and soil temperature change. Crop resistance model was adopted to analyze heat energy exchange on surface layer. Using the model, simulations were conducted for 6 fine days in 6 different months using meteorological data measured at other experimental stations. The results show different thermal behavior of the three surface conditions. Temperature order from the highest are bare, grass and paddy; and evaporation order from the highest are paddy, grass and bare.

Evaluation of Evapotranspiration by Using Numerical Model and Remotely Sensed Surface Temperature Data

Evapotranspiration (ET) involves a complex set of processes which are influenced by the local conditions. These conditions are characterized by meteorological and ground surface condition. ET for large area with different land covers were estimated by evaluating the energy balance components for each land use, using a numerical model of the energy balance which includes differential equations of wind velocity, specific air humidity, potential air temperature, soil temperature and soil moisture. Remotely observed surface temperatures were used to modify the parameters used within the model. The inputs for this numerical model are direct and diffused solar radiation, solar elevation, long wave radiation, surface temperature, ground moisture, crop transpiration resistance, leaf area index, crop canopy architecture, wind velocity, air temperature and relative humidity. The extinction of solar radiation intensity as it passes the land cover canopy is estimated by treating the plant canopy as a single ‘big leaf’. As for the upper boundary of this system, constant values of wind velocity, potential air temperature, and specific humidity were used at the height of 100 m above ground. The total daily latent heat of every land use for paddy field, bare soil and forest are 12.5 MJ.m-2d-1, 11.2 MJ.m-2d-1 and 15 MJ.m-2d-1. These values are equal to 5, 4.5 and 6 mm of water.

Water Regulation in Tidal Agriculture using Wetland Water Level Control Simulator

A multidisciplinary study with the main objective to develop an environmentally sound water management to be applied in peat land agriculture has been conducted. The output of this study is a water level controller, a computer software that incorporates two dimensional equation of water flow in saturated soil and fuzzy controller with taking into account the soil physical properties of peat soil under consideration and its hydrological conditions. By using this system the excessive water extraction or reduction, of which in many tropical peat soils will cause soil subsidence due to irreversible deformation, can be prevented. The system has been tested by conducting field experiments for some tropical peat lands in South Sumatra, Indonesia, to see the applicability of the system in maintaining the desired water levels. The actual water level was measured by means of pressure transducer while water inflow and outflow were undertaken by the use of electric pumps. A simulator, based on equations of soil water flow, tides, and control algorithm, was developed and used to intensify the research, minimize failure, and cost of field experiment or application. This simulator can also be used as a tool for obtaining appropriate size of specific peat land agriculture within the capability of water management. Hopefully, this system can be used as a valuable assistance in designing an agricultural plot converted from peat land and enables the determination of operation cost of water management in a field scale.